One important consideration in manufacturing pre-filled syringes and cartridges or other vessels (such as vials) for storing or other contact with fluids, for example, is that the contents of the pharmaceutical package or other vessel desirably will have a substantial shelf life. During this shelf life, it is important to isolate the material filling the pharmaceutical package or other vessel from the vessel wall containing it, or from barrier coating or layers or other functional coating or layers applied to the pharmaceutical package or other vessel wall to avoid leaching material from the pharmaceutical package or other vessel wall, barrier coating or layer, or other functional coating or layers into the prefilled contents or vice versa.
Commonly, after it is filled, a prefilled syringe or cartridge is capped at the distal end, as with a needle shield or other type of cap, and is closed at the proximal end by its drawn plunger tip or piston. The prefilled syringe or cartridge can be wrapped in a sterile package before use. To use the prefilled syringe or cartridge, the packaging and needle shield or other type of cap are removed, optionally a hypodermic needle or other type of dispenser is attached (if not already present), the delivery conduit or syringe is moved to a use position (such as by inserting the hypodermic needle into a patient's blood vessel or into apparatus to be rinsed with the contents of the syringe), and the plunger tip or piston is advanced in the barrel to inject the contents of the barrel. If a cartridge is being used, it is also placed into a mechanism that mechanically advances the piston to make an injection, for example using an injection spring.
An important consideration regarding medical syringes and cartridges, in particular prefilled syringes and cartridges, is to ensure that the prefilled syringe or cartridge has container closure integrity, meaning that it has been determined to be sterile, and not subject to subsequent microbiological contamination, by a mechanical, non-destructive test method. Other important considerations are that when the syringe or cartridge is being manufactured and before it has been filled, it does not have defects that would prevent the filled package from having the necessary container closure integrity. It is also important to manufacture a medical syringe or cartridge that is economical to manufacture, yet will provide the necessary container closure integrity, which can be verified by a test performed on every piece manufactured (a concept sometimes referred to as “100% inspection”).